Especially since Marx, in practical terms, equality has been assuming increasing importance in our lives.

Locke is optimistic, while Plato is pessimistic, and this is an important subjective difference between their opinions; a glass can be half empty or half-full, depending on who looks at it.

Marx and Rousseau are also optimistic for the future but see their contemporaneous societies as something like an evil clockwork; the difference between them resides in the fact that Marx predicts that changes would eventually take place in a violent way and as the result of a struggle.

This is interesting, since his outlook puts Marx in direct opposition to Plato's views, since the latter, being pessimistic, believes in gradual changes and is himself an aristocrat. Locke is optimistic because he believes in human beings brought together by reason and convenience; Rousseau believes that the society of his time and place is evil because it is, in a broad sense, guilty of man's evilness.

One of the few things in which Plato and Marx seem to have similar outlooks is the very low importance that they assign to individual human beings in contrast to the priority that they give to human groups and the development of power thorough these, instead as of originated from individuals.